Hey dwkdnvr :
If you havent already look up the Gassification Archive.
Yes, I have spent a fair bit of time there, and on the more 'consumer grade' Yahoo group. I'm currently working through a few books I picked up from Tom Reed's site as well, which help to pull things together
And shreded wood products even compressed won't work they have to chunks or blocks in the 1 to 2 inch range with a moister content below 30%
Well, that's not really consistent with what I've found so far - at least in theory. From what I can tell, virtually any wood product can be gasified, but the challenging aspects are
a) gasifier design is critically dependent on feedstock, and vice-versa. If a gasifier is designed for wood blocks, it won't work on shredded material for example
b) getting it to run predictably without bridging
c) ash content (this is one place I'd be worried about pine needles)
d) getting a reliable continuous fuel feed.
This is in addition to the question of whether it's even possible to actually create compressed briquettes out of the type of stuff I have around with reasonable effort. Certainly I can' t see loose shredded material being a viable fuel - pyrolisis would happen too fast and unpredictably, and I'd imagine that ash and bridging would be a real problem.
Doug
I read and tinkered for several months with a small copy of the Fluidyne pioneer class before I abandoned the idea of generating my own hydro with wood.
Well, it is pretty obvious to me that if one is looking for a full-time/production grade solution for power, woodgas is not the answer. Far too finickey to be a 'start and forget' solution at the small scale. For thermal I think it has promise, but since our cabin is in southern Colorado we have solar thermal opportunities out the wazoo, and so just don't have that much in the way of thermal needs. However, since my application is for a weekend cabin, I may be able to make use of something like a '2 hour batch run' setup to recharge batteries etc, and it's the only way I can see to get power out of the 1 resource I have for 'free'.
Even so, I'm beginning to wonder whether simply trying to compost all the wood waste and generate decent soil to try to grow a small ~1/4 acre patch of sunflowers might not be a better approach - run them through an oil press for maybe 25-50 gallons of SVO per year. Seems like a lot of work (and water, which is very scarce) for maybe $100 of fuel payoff, though.